Precast reinforced concrete form

ABSTRACT

The present invention relates to forms for forming poured-in-situ vertical concrete walls, columns, floors and parapets of residential or commercial buildings, in particular a form having at least one precast reinforced concrete panel.

FIELD OF THE INVENTION

This invention generally relates to forms for forming poured-in-situ vertical concrete walls, columns, floors and parapets of residential or commercial buildings, in particular a form having at least one precast reinforced concrete panel.

DESCRIPTION OF THE PRIOR ART

Concrete wall construction has been historically mostly relegated to the cast in place method through the installation of formwork. This basically involves setting up the forms in advance, placing the required rebar and any external reinforcement to secure the forms in place when the concrete is poured, then pouring the concrete inside the forms. The concrete is allowed to cure sufficiently to enable the forms to be removed (stripped). It may be necessary after the forms are removed to brace the walls while the concrete continues to cure. The cycle therefore requires these operations to be performed on site. The schedule consequently becomes a critical factor because all these elements get on the critical path. Additionally, the formwork is not the best method in terms of quality, requiring several touch ups and patching to the walls after stripping.

SUMMARY OF THE INVENTION

In one embodiment, the present invention provides a form for forming poured-in-situ vertical concrete walls of residential or commercial buildings wherein the vertical walls are exterior walls below grade. The form comprises at least one precast reinforced concrete panel said panel having an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface facing the building interior. The panel has first and second vertical sides and a top end and a bottom end. The form further comprises a plurality of vertical reinforcing trusses, each of said trusses having a longitudinal header, said header cast into the panel, and each of said trusses having horizontal reinforcing members extending from said header outwardly through the inside surface of said panel.

The forms of the present invention are intended to include the reinforcing rebar for the wall section to be poured behind the form as required by the applicable building code. The only rebar required to be placed on site is that required between adjacent forms. Use of the present invention thereby significantly reduces forming set up time on site.

The forms of the present invention are intended to remain in place after the concrete is poured. The outside surface of the precast panel is intended to form the visible surface facing the building interior. The use of the present invention further significantly saves time on site by eliminating the need and in the case of below grade walls the difficulty in stripping (removing the forms) after the poured concrete is cured.

In another embodiment, the present invention provides a precast reinforced concrete form for forming poured-in-situ vertical concrete walls of residential or commercial buildings wherein the vertical walls are exterior or interior walls above or below grade. The precast reinforced concrete form comprises a pair of precast reinforced concrete panels. Each of the precast reinforced concrete panels has an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface, first and second vertical sides and a top end and a bottom end. The form further comprises a plurality of horizontal reinforcing trusses. Each of said trusses typically has a first longitudinal header cast into one panel, horizontal reinforcing members extending from said first header outwardly through the inside surface of said panel to a second horizontal header cast into the second panel. Each of the longitudinal headers can be further reinforced by vertical longitudinal reinforcement rods linking each of said trusses. The longitudinal headers, horizontal reinforcing members and longitudinal reinforcement rods can be formed from rebar, threaded wire rod or other acceptable material as required pursuant to building codes in the jurisdiction the forms are being used.

Another embodiment of the present invention provides a precast reinforced concrete form for forming poured-in-situ vertical concrete stairwell walls of residential or commercial buildings. The precast reinforced concrete form comprises a pair of precast reinforced concrete panels. Each of the precast reinforced concrete panels has an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface, first and second vertical sides and a top end and a bottom end. The form further comprises a plurality of horizontal reinforcing trusses, each of said trusses having a first longitudinal header, said header cast into one of the panels and horizontal reinforcing members extending from said header outwardly through the inside surface of said panel to a second horizontal header cast into the other panel. Each of the longitudinal headers may be further reinforced by vertical longitudinal reinforcement rods linking each of said trusses. The longitudinal headers, horizontal reinforcing members and longitudinal reinforcement rods can be formed from rebar, threaded wire rod or other acceptable material as required pursuant to building codes in the jurisdiction the forms are being used.

Another embodiment of the present invention provides a precast reinforced concrete form for forming poured-in-situ vertical rectangular columns of residential or commercial buildings. The precast reinforced concrete form comprises a pair of precast reinforced concrete panels. Each of the precast reinforced concrete panels has an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface, first and second vertical sides and a top end and a bottom end. The form further comprises a plurality of horizontal reinforcing members cast into the panels. The horizontal and vertical reinforcing members can be formed from rebar, threaded wire rod or other acceptable material as required pursuant to building codes in the jurisdiction the forms are being used.

Another embodiment of the present invention provides a precast reinforced concrete form for forming poured-in-situ vertical circular columns of residential or commercial buildings. The precast reinforced concrete form comprises a circular precast reinforced concrete panel with a hollow center. The circular precast reinforced concrete panel has an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface and a top end and a bottom end. The form further comprises a plurality of horizontal and vertical reinforcing members cast into the panel following the shape of the panel. The horizontal and vertical reinforcing members can be formed from rebar, threaded wire rod or other acceptable material as required pursuant to building codes in the jurisdiction the forms are being used.

Another embodiment of the present invention provides a precast reinforced concrete form for forming poured-in-situ vertical square columns of residential or commercial buildings. The precast reinforced concrete form comprises a square precast reinforced concrete panel with a hollow center. The square precast reinforced concrete panel has an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface and a top end and a bottom end. The form further comprises a plurality of horizontal and vertical reinforcing members cast into the panel following the shape of the panel. The horizontal and vertical reinforcing members can be formed from rebar, threaded wire rod or other acceptable material as required pursuant to building codes in the jurisdiction the forms are being used.

Another embodiment of the present invention provides a precast reinforced concrete form for forming poured-in-situ vertical parapets of residential or commercial buildings. The precast reinforced concrete form comprises a pair of precast reinforced concrete panels. Each of the precast reinforced concrete panels has an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface, first and second vertical sides and a top end and a bottom end. The form further comprises a plurality of horizontal reinforcing trusses, each of said trusses having a first longitudinal header, said header cast into one of the panels and horizontal reinforcing members extending from said header cast into the other panel. Each of the longitudinal headers may be further reinforced by vertical longitudinal reinforcement rods linking each of said trusses. The longitudinal headers, horizontal reinforcing members and longitudinal reinforcement rods can be formed from rebar, threaded wire rod or other acceptable material as required pursuant to building codes in the jurisdiction the forms are being used.

Another embodiment of the present invention provides a precast reinforced concrete form for forming poured-in-situ vertical mono walls of residential or commercial buildings. The precast reinforced concrete form comprises a single precast reinforced concrete panel. The precast reinforced concrete panel has an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface, first and second vertical sides and a top end and a bottom end. The form further comprises a plurality of horizontal reinforcing trusses, each of said trusses having a first longitudinal header, said header cast into one of the panels and horizontal reinforcing members extending from said header cast into the cavity to be filled with concrete. Each of the longitudinal headers may be further reinforced by vertical longitudinal reinforcement rods linking each of said trusses. The longitudinal headers, horizontal reinforcing members and longitudinal reinforcement rods can be formed from rebar, threaded wire rod or other acceptable material as required pursuant to building codes in the jurisdiction the forms are being used.

The use of the forms of the present invention provide the jobsite with a method of forming poured-in-situ vertical concrete walls faster than using conventional methods as stay in place formwork. It will also avoid quality issues by prefabricating the forms in a controlled environment where the tolerances allow for far less mistakes than on a jobsite with site formwork. Therefore, there is a significant improvement in terms of quality with very few repairs and touch ups necessary after concrete pour.

The forms of the present invention are light enough to be erected on site by the available regular tower crane and incorporate the reinforcing steel foreseen by the design and applicable codes.

In another embodiment the present invention provides a method of making a form for forming poured-in-situ vertical concrete walls of residential or commercial buildings the form comprising at least one precast reinforced concrete panel, the method comprising:

a. forming a mould for one of the precast panels, b. positioning a plurality of vertical reinforcing trusses off the base of the form for the first precast panel, each of said trusses having a pair of longitudinal headers, said headers to be cast into the panel, and each of said trusses having horizontal reinforcing members extending from said headers outwardly through the inside surface of said panel, c. pouring concrete into the mold with a sufficient cover to retain the pair of longitudinal headers, curing it, rotating it after reaching the required strength.

In another embodiment the present invention provides a system of erecting formwork for forming poured-in-situ vertical concrete walls of residential or commercial buildings comprising:

-   -   a plurality of forms for forming poured-in-situ vertical         concrete walls of residential or commercial buildings wherein         the vertical walls are exterior walls below grade according to         the description noted above are erected on spacers that allow         for a concrete base as wide as the form.     -   to ensure the loads are adequately flowing through adjacent         forms, dowels may be protruding from the structure below and         going in between the prefabricated panels of the forms.     -   when the forms are being erected over a concrete slab, the         prefabricated panels will be placed over slab dowels that were         left protruding from the slab itself.     -   some rebar protruding from the wall below can be incorporated         into the new forms being erected.     -   during the erection, the forms will be lifted in place by the         tower crane and then supported laterally and kept vertical by         temporary props to be connected to the wall.     -   when enough forms have been erected and the onsite rebar has         been placed, concrete will be poured in between the precast         panels until reaching the full height of the panels or could be         poured in lifts, depending on the site needs and on the design.

In another embodiment, the present invention provides a method for forming poured-in-situ vertical concrete walls for a stairwell using a plurality of precast forms, each form comprising at a pair of precast reinforced concrete panels said panels having an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface, first and second vertical sides and a top end and a bottom end, and said form further comprising a plurality of vertical reinforcing trusses, each of said trusses having a first longitudinal header section, said header section cast into one of said panels, and each of said trusses having horizontal reinforcing members extending from said header sections outwardly through the inside surface of said panel to a second header section cast into the other one of said panels, said method comprising:

-   -   along one end of the stairwell, a precast concrete form as         described above is erected, after erection of the first the         precast concrete form, the formwork for the long wall of the         stairwell is erected using another precast concrete form;     -   the formwork for the second end of the stairwell is erected next         using another of the precast concrete forms;     -   lastly the formwork for the doorway side wall of the stairwell         is erected using the another of the precast concrete forms.

The method for forming poured-in-situ vertical concrete walls for a stairwell may further comprises once the precast concrete forms have been setup for the stairwell concrete walls, a precast landing is attached to the inside surface of the panels adjacent their top ends.

The method for forming poured-in-situ vertical concrete walls for a stairwell may further include having a set of precast stairs set on the landing and floor of the stairwell.

Further features of the invention will be described or will become apparent in the course of the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be more clearly understood, the preferred embodiment thereof will now be described in detail by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic view of one embodiment of a precast reinforced concrete form for forming poured-in-situ vertical concrete walls of residential or commercial buildings wherein the vertical walls are exterior walls below grade according to the present invention.

FIG. 2 is top plan view of the precast reinforced concrete form of FIG. 1.

FIG. 3 is a side view in cross-section of the precast reinforced concrete form of FIG. 1.

FIG. 4A is a perspective view of a precast reinforced concrete form of FIG. 1 erected on a footing.

FIG. 4B is an end view of the precast reinforce concrete form of FIG. 4A;

FIG. 5 is another embodiment of a precast reinforced concrete form for forming poured-in-situ vertical concrete walls of residential or commercial buildings wherein the vertical walls are exterior or interior walls above or below grade according to the present invention

FIG. 6 is a top plan view of the precast reinforced concrete form of FIG. 5.

FIG. 7 is a side view in cross-section of the precast reinforced concrete form of FIG. 5.

FIGS. 8A-8D show another embodiment of a precast reinforced concrete form for forming poured-in-situ vertical concrete stairwell walls of residential or commercial buildings, according to the present invention.

FIG. 9 is a schematic representation of how the forms of FIGS. 8A-8D are erected to enable the stairwell walls to be poured.

FIGS. 10A-10D are a series of cross-sectional views of the connection between adjacent forms as shown in 8A-8D.

FIG. 11 is a top plan view of a precast landing attached to the top of the precast reinforced concrete forms of FIGS. 8A-8D erected as a stairwell.

FIG. 12 is a side plan view of one embodiment of a set of precast stairs attached to the landing shown in FIG. 11.

FIG. 13 is a top view in partial cross section showing one embodiment of means for lifting a precast reinforced concrete form according to the present invention.

FIG. 14A is a partial perspective schematic view showing another embodiment of a precast concrete form for forming a square column according to the present invention.

FIG. 14B is side plan view in partial cross section of one side of the precast form of FIG. 14A;

FIG. 14C is top plan view of the precast form of FIG. 14B;

FIG. 15A is a perspective schematic view showing another embodiment of a precast concrete form for forming a rectangular column according to the present invention.

FIG. 15B is side plan view in partial cross section of one side of the precast form of FIG. 15A;

FIG. 15C is top plan view of the precast form of FIG. 15B;

FIG. 16A is side plan view in partial cross section of for forming a circular column according to the present invention.

FIG. 16B is top plan view of the precast form of FIG. 16A;

FIG. 17A is a perspective view showing another embodiment of a precast concrete form for forming parapets according to the present invention.

FIG. 17B is a plan view in partial cross section of one end of the precast form of FIG. 17A;

FIG. 18 is a perspective view showing installation of precast stairs in conjunction with precast concrete forms according to the present invention.

Similar references are used in different figures to denote similar components

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1-3, an embodiment of a precast reinforced concrete form for forming poured-in-situ vertical concrete walls of residential or commercial buildings wherein the vertical walls are exterior walls below grade, according to the present invention, is generally indicated at 1. Referring to FIG. 1, the form 1 comprises at least one precast reinforced concrete panel 2. The precast reinforced concrete panel 2 in the embodiment shown has an inside surface 3 facing the space in which the poured-in-situ concrete is to be placed and an outside surface 4 facing the building interior, first and second vertical sides 5, 6 and a top end 7 and a bottom end 8. The outside surface 4 can be a smooth finished concrete surface. The precast reinforced concrete panel 2 preferably has a nominal thickness of 60-150 mm and may be formed from air or non-air entrained concrete have the required psi prescribed by applicable codes. Typical values are 3000-7000 psi.

The form 1 further comprises a plurality of interconnected horizontal reinforcing trusses 9. Each of said trusses 9 have a first longitudinal header section, generally indicated at 10, cast into the panel 2. In the embodiment shown the first longitudinal header section 10 comprises a pair of parallel longitudinal headers 10A and 10B. Each of said trusses 9 have horizontal reinforcing members extending from said header section outwardly through the inside surface 3 of said panel 3. In the embodiment shown horizontal reinforcing members 11 extend outwardly from the first longitudinal header 10A in pairs that are spaced apart at the point of connection with the first longitudinal header 10A and inclined downwardly to connect to a second longitudinal header section 12, offset vertically down from the first longitudinal header 10A, at a common point of connection 15. In the embodiment shown horizontal reinforcing members 14 extend outwardly from the longitudinal header 10B in pairs that are spaced apart at the point of connection with the longitudinal header 10B and inclined upwardly to connect to the second longitudinal header section 12, offset vertically up from the longitudinal header 10B, at a common point of connection 16. Each of the longitudinal headers 10A, 10B, 12, may be further reinforced by vertical longitudinal reinforcement rods 15A linking each of said trusses 9. The longitudinal headers 10A, 10B, 12, horizontal reinforcing members 11, 14 and longitudinal reinforcement rods 15A can be formed from rebar, threaded wire rod or other acceptable material as required pursuant to building codes in the jurisdiction the forms are being used. Additional rebar can be placed in the form on site if needed to match design requirements. The precast panel may differ in dimensions depending on each individual application of the precast reinforced concrete forms.

The concrete form 1 of FIGS. 1-3 is fabricated by creating a mold the size and shape of precast panel 2 and positioning the plurality of interconnected trusses 9 that have been pre-fabricated above the base of the mold with the longitudinal header section 10 set off the base of the mold. Concrete is then poured into the mold to form precast panel 2 with a sufficient cover of concrete over the longitudinal header section 10. An adequate cover needs to be calculated to avoid the longitudinal header section 10 being extracted from the precast panels during use. Codes may require typically a 30 mm cover for exterior walls. The precast panel 2 is allowed to cure, until the precast panel 2 has reached the required strength which may take a day or longer. The plurality of interconnected trusses 9 create a lattice that provide stability during the precast reinforced concrete form handling and to resist the hydraulic pressure of the wet concrete when the concrete is poured in situ.

Once the concrete precast panel 2 has sufficiently hardened, the precast reinforced concrete forms 1 can be transported to the site. The precast reinforced concrete forms 1 are placed around the outside of the intended building near a retaining wall or a rock wall so that the concrete is poured in between the precast panel 2 of the precast reinforced concrete form 1 and the retaining wall or rock wall. A plurality of precast reinforced concrete forms 1 are placed standing on their bottom ends 8 resting on spacers 15B that allow for a concrete base 16A as wide as the precast reinforced concrete form 1. The spacers are made of any material that is durable, does not corrode and deemed appropriate for each application including but not limited to plastic. To ensure the loads are adequately flowing through the precast reinforced concrete form 1, dowels 17 can be protruding from the structure below and going in between the plurality of trusses 9 of the precast reinforced concrete form 1.

During the erection, the precast reinforced concrete forms 1 will be lifted in place by the tower crane and then supported laterally and kept vertical by temporary A-frame props 18, see FIGS. 4A & 4B, to be connected at one end to the wall at generally ⅔ the panel's height and at the other end to the slab or grade the form is resting on. Where the precast reinforced concrete forms are erected over a slab it may be necessary to install sheer brackets or support at the bottom end 8 of each form. The precast reinforced concrete panel in FIGS. 4A & 4B has an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface, first and second vertical sides and a top end and a bottom end. The form further comprises a plurality of horizontal reinforcing trusses, each of said trusses having a first longitudinal header, said header cast into one of the panels and horizontal reinforcing members extending from said header cast into the cavity to be filled with concrete. Each of the longitudinal headers may be further reinforced by vertical longitudinal reinforcement rods linking each of said trusses. The longitudinal headers, horizontal reinforcing members and longitudinal reinforcement rods can be formed from rebar, threaded wire rod or other acceptable material as required pursuant to building codes in the jurisdiction the forms are being used.

Each concrete form 1 should preferably be provided with means to assist the crane on site lifting the forms into place. One possible means to assist lifting the forms 1 of the present invention into place is illustrated in FIG. 13. The lifting means illustrated in FIG. 13 includes a coil tie member 18A cast into the top end 7 of precast panel 2 so that an eyebolt 19 can be threaded into the coil tie 18 to allow the crane a lifting point on the form 1.

Referring to FIGS. 5-7, another embodiment of a precast reinforced concrete form 20 for forming poured-in-situ vertical concrete walls of residential or commercial buildings wherein the vertical walls are exterior or interior walls above or below grade according to the present invention is illustrated. In this embodiment the precast reinforced concrete form 20 comprises a pair of precast reinforced concrete panels 21, 22. Each of the precast reinforced concrete panels 21, 22 in the embodiment shown has an inside surface 23 facing the space in which the poured-in-situ concrete is to be placed and an outside surface 24, first and second vertical sides 25, 26 and a top end 27 and a bottom end 28. The form 20 further comprises a plurality of horizontal reinforcing trusses 29, each of said trusses 29 having a first longitudinal header section generally indicated at 30A cast into the panel 21. In the embodiment shown the first longitudinal header section 30A includes a pair of parallel longitudinal headers 30, 31. Each of said trusses 29 having horizontal reinforcing members extending from the first header section 30A extending outwardly through the inside surface 23 of said panel 21 to a second horizontal header 34 cast into the panel 22. In the embodiment shown horizontal reinforcing members 32 extend from said header 30 and horizontal reinforcing members 33, extend from header 31, outwardly through the inside surface 23 of said panel 21 to a second horizontal header 34 cast into the panel 22. Each of the longitudinal headers 30, 31, 34 may be further reinforced by vertical longitudinal reinforcement rods 35 linking each of said trusses 29. The longitudinal headers 30, 31, 34, horizontal reinforcing members 32, 33 and longitudinal reinforcement rods 35 can be formed from rebar, threaded wire rod or other acceptable material as required pursuant to building codes in the jurisdiction the forms are being used.

One form of the connections between adjacent precast reinforced concrete forms 1 or 20 to ensure the proper behavior of the structure are shown in FIGS. 10A-10D. The Figures show the precast reinforced concrete forms 20 but similar connections are appropriate with suitable modifications for precast reinforced concrete forms 1.

Referring to FIG. 10A, if there is a corner connection, it is likely that some rebar needs to be installed in the space between the panels 21, 22 of adjoining forms 20. This installation may require some modifications of the panels 21, 22 to facilitate the correct positioning of this additional rebar. For example, small portions of the precast panels 21 can be eliminated so the forms 20 fit closely with minimal on-site formwork used. The additional rebar shown in FIG. 10A is a plurality of pairs of elongated U-shaped rebar sections 41, 42. This flexibility allows the installer to see some of his/her specific needs incorporated in the design of the panels. This means that in places where the rebar installed on site is particularly congested, the precast reinforced concrete form 20 can be fabricated with specific openings in its precast panels 21, 22. Also, a corner bracket (not shown) may be installed on site to reinforce the corner area during concreting operations. This corner bracket may or may not be required depending on the pour sequence and the relevant hydraulic pressures.

FIG. 10B shows a wall end of a precast reinforced concrete forms 20 where the open side of an end panel 21, 22 of precast reinforced concrete forms 20 is enclosed with end formwork 43. This may be installed on site or at the plant during fabrication of the forms.

FIG. 10C shows a bottom wall connection of precast reinforced concrete forms 20 to a slab, footing or top of another form 20 where the additional rebar is vertical upstanding dowels 44.

FIG. 10D shows the wall connection between adjacent forms 20. In this case the additional rebar is a plurality of horizontal sections extending between the space between panels 21, 22 of each form 20.

Finally, when enough precast reinforced concrete forms have been erected and the onsite rebar 3A has been placed, concrete will be poured in between the prefabricated elements. The concrete could be poured until reaching the full height of the panels 2, 21, 22 or could be poured in lifts, depending on the site needs and on the design of the metal connectors of the precast reinforced concrete form 1 or 20.

Similarly, and referring to FIG. 7, when the precast reinforced concrete form 1 is being erected over a concrete slab 19B, the prefabricated panels 2 will be placed over the slab dowels 19A that were left protruding from the slab itself. Also, some rebar 3A protruding from the precast reinforced concrete form 1 below can be incorporated into the new precast reinforced concrete form 1 being erected.

Another embodiment of a precast reinforced concrete form 50 for forming poured-in-situ vertical concrete stairwell walls of residential or commercial buildings according to the present invention is illustrated in FIGS. 8A-8D. The precast reinforced concrete form 50 in each of FIGS. 8A-8D comprises a pair of precast reinforced concrete panels 51, 52. Each of the precast reinforced concrete panels 51, 52 in the embodiment shown has an inside surface 53 facing the space in which the poured-in-situ concrete is to be placed and an outside surface 54, first and second vertical sides 55, 56 and a top end 57 and a bottom end 58. The form 50 further comprises a plurality of horizontal reinforcing trusses 59, each of said trusses 59 having a first longitudinal header section 60A cast into the panel 51. In the embodiment shown the first longitudinal header section 60A comprises a pair of longitudinal headers 60, 61, and each of said trusses 59 having horizontal reinforcing members 62, extending from said header 60 and horizontal reinforcing members 63, extending from said header 61 outwardly through the inside surface 53 of said panel 51 to a second horizontal header 64 cast into the panel 52. Each of the longitudinal headers 60, 61, 64 may be reinforced by vertical longitudinal reinforcement rods 65 linking each of said trusses 59. The longitudinal headers 60, 61, 64, horizontal reinforcing members 62, 63 and longitudinal reinforcement rods 65 can be formed from rebar, threaded wire rod or other acceptable material as required pursuant to building codes in the jurisdiction the forms are being used.

Each of the concrete forms 50 shown in FIGS. 8A-8D have had the alignment of the panels 51, 52 modified to accommodate the formation of the stairwell walls when the forms are joined.

FIG. 9 shows schematically in sequence how the precast reinforced concrete forms shown in FIGS. 8A to 8D are erected to create the formwork for the stairwell walls. Along one end of the stairwell, the precast concrete form 50 shown in FIG. 8D is erected. This form has panel 51 narrower than panel 52 so one side 56 of panel 51 is setback from the corresponding side 56 of panel 52.

After erection of the first the precast concrete form 50, the formwork for the longwall of the stairwell is erected using the precast concrete form 50 shown in FIG. 8B. This form has panel 51 narrower than panel 52 so both sides 55, 56 of panel 51 are setback from the corresponding side 55, 56 of panel 52.

The formwork for the second end of the stairwell is erected next using a precast concrete form 50 shown in FIG. 8C. This form has panel 51 narrower than panel 52 so again both sides 55, 56 of panel 51 are setback from the corresponding side 55, 56 of panel 52.

Lastly the formwork for the doorway side wall of the stairwell is erected using the precast concrete form 50 shown in FIG. 8A. This form has panel 51 narrower than panel 52 so the side 55 of panel 51 is setback from the corresponding side 55 of panel 52. The other side 56 of form 50 is enclosed on site.

Once the precast concrete forms 50 have been setup for the stairwell concrete walls, a precast landing 70 as shown in FIG. 11 can be attached to the inside surface 53 of the panels 51 adjacent their top ends 57 or in some cases half way down the form. A set of precast stairs 80 can be set on the landing 70 and floor of the stairwell as shown in FIG. 12 or FIG. 18.

FIGS. 14A, 14B and 14C show a precast form according to the present invention for forming a square column. The precast reinforced concrete form comprises a square precast reinforced concrete panel with a hollow center. The square precast reinforced concrete panel has an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface and a top end and a bottom end. The form further comprises a plurality of horizontal and vertical reinforcing members cast into the panel following the shape of the panel. The horizontal and vertical reinforcing members can be formed from rebar, threaded wire rod or other acceptable material as required pursuant to building codes in the jurisdiction the forms are being used The form has four vertical side walls of pre-cast concrete each side 50-70 mm thick with reinforced rebar typically 15 mm to 25 mm diameter, and sticking up from the top end of each side wall. The form is typically 12 inches to 36 inches square with the interior space between the four vertical side walls filled with in-situ poured concrete. The forms may be any height.

FIGS. 15A, 15B and 15C show a precast reinforced concrete form for forming poured-in-situ vertical rectangular columns of residential or commercial buildings. The precast reinforced concrete form comprises a pair of precast reinforced concrete panels. Each of the precast reinforced concrete panels has an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface, first and second vertical sides and a top end and a bottom end. The form further comprises a plurality of horizontal and vertical reinforcing members cast into the panels. The horizontal and vertical reinforcing members can be formed from rebar, threaded wire rod or other acceptable material as required pursuant to building codes in the jurisdiction the forms are being used.

FIGS. 16A and 16B show a precast form according to the present invention for forming poured-in-situ vertical circular columns of residential or commercial buildings. The precast reinforced concrete form comprises a circular precast reinforced concrete panel with a hollow center. The circular precast reinforced concrete panel has an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface and a top end and a bottom end. The form further comprises a plurality of horizontal and vertical reinforcing members cast into the panel following the shape of the panel. The horizontal and vertical reinforcing members can be formed from rebar, threaded wire rod or other acceptable material as required pursuant to building codes in the jurisdiction the forms are being used.

FIGS. 17A and 17B show another embodiment of a precast reinforced concrete form for forming poured-in-situ vertical parapets of residential or commercial buildings. The precast reinforced concrete form comprises a pair of precast reinforced concrete panels. Each of the precast reinforced concrete panels has an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface, first and second vertical sides and a top end and a bottom end. The form further comprises a plurality of horizontal reinforcing trusses, each of said trusses having a first longitudinal header, said header cast into one of the panels and horizontal reinforcing members extending from said header cast into the other panel. Each of the longitudinal headers may be further reinforced by vertical longitudinal reinforcement rods linking each of said trusses. The longitudinal headers, horizontal reinforcing members and longitudinal reinforcement rods can be formed from rebar, threaded wire rod or other acceptable material as required pursuant to building codes in the jurisdiction the forms are being used.

The precast concrete forms of the present invention preferably have means incorporated into the top end of the forms to enable the forms to be lifted by the crane and put into place. FIG. 13 shows one possible embodiment of such lifting means.

A beneficial feature is the ability of the precast reinforced concrete form 1 or 20 to create continuity with the structure below. The precast reinforced concrete form 1 or 20 is to create continuity with the structure below. The precast reinforced concrete form 1 or 20 may be erected on spacers 91 that allow for a concrete base 92 as wide as the precast reinforced concrete form 1 or 20. The spacers are made of any material that is durable, does not corrode and deemed appropriate for each application including but not limited to plastic. To ensure the loads are adequately flowing through the precast reinforced concrete form 1, 20, dowels 93 can be protruding from the structure below and going in between the prefabricated panels 2, 21, 22 of the precast reinforced concrete form 1, 20. Similarly, and referring to FIG. 4, when the precast reinforced concrete form 1 is being erected over a concrete slab, the prefabricated panels 2 will be placed over the slab dowels that were left protruding from the slab. Also, some rebar protruding from the precast reinforced concrete form 1, 20 below can be incorporated into the new precast reinforced concrete form 1, 20 being erected. During the erection, the precast reinforced concrete form 1 will be lifted in place by the tower crane and then supported laterally and kept vertical by temporary props to be connected to the wall in specific prop locations provided by the supplier of the precast reinforced concrete form 1.

While the principles of the invention have been shown and described in connection with specific embodiments, it is to be understood that such embodiments are by way of example and are not limiting as is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details illustrated in the drawings. Other modifications and applications, or equivalents, will occur to those skilled in the art. The terms “having”, “comprising” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required”. Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and attached drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims that follow. The scope of the disclosure is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather one or more. All structural and functional equivalents to the elements of the embodiment described throughout the disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and intended to be encompassed by the claims. For example, some variations to the precast reinforced concrete form include but are not limited to precast reinforced concrete forms integrated with precast stair systems (see FIGS. 8 and 9), windows, doors or other architectural or structural elements; referring to FIG. 2, precast reinforced concrete forms integrated with the foundation below where part of the rebar of the foundation is already incorporated in the bottom part of the precast reinforced concrete form in order to improve the connection between the precast reinforced concrete form and the foundation; referring to FIG. 6, a precast reinforced concrete form using bolts to eliminate the need for welding. 

What is claimed is:
 1. A form for forming poured-in-situ vertical concrete walls of residential or commercial buildings wherein the vertical walls are exterior walls below grade, the form comprising at least one precast reinforced concrete panel, the precast reinforced concrete panel has an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface facing the building interior, first and second vertical sides and a top end and a bottom end, the form further comprises a plurality of interconnected horizontal reinforcing trusses, each of said trusses having a first longitudinal header section, said header section cast into the panel, and each of said trusses having horizontal reinforcing members extending from said header section outwardly through the inside surface of said panel to connect to a second longitudinal header.
 2. A form according to claim 1 wherein the plurality of interconnected horizontal reinforcing trusses are further reinforced by vertical longitudinal reinforcement rods linking each of said trusses.
 3. A form according to claim 1 or 2 wherein the first longitudinal header section comprises a parallel first and second longitudinal headers.
 4. A form for forming poured-in-situ vertical concrete walls of residential or commercial buildings the form comprising a pair of precast reinforced concrete panels, each of the precast reinforced concrete panels having an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface, first and second vertical sides and a top end and a bottom end, the form further having a plurality of horizontal reinforcing trusses, each of said trusses having a first pair of longitudinal headers, said headers cast into one of said panels, and each of said trusses having horizontal reinforcing members extending from said one of the pair of headers and horizontal reinforcing members extending from the other of said pair of headers outwardly through the inside surface of said one panel to a second horizontal header cast into the other panel wherein each of the longitudinal headers is further reinforced by vertical longitudinal reinforcement rods linking each of said trusses.
 5. A precast reinforced concrete form for forming poured-in-situ vertical rectangular columns of residential or commercial buildings, comprising a pair of precast reinforced concrete panels, each of the precast reinforced concrete panels has an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface, first and second vertical sides and a top end and a bottom end, wherein the precast form further comprises a plurality of horizontal and vertical reinforcing members cast into the panels.
 6. A precast reinforced concrete form for forming poured-in-situ vertical square columns of residential or commercial buildings, comprising a square precast reinforced concrete panel with a hollow center, an inside surface facing the space in which the poured-in-situ concrete is to be placed, an outside surface and a top end and a bottom end, wherein the form further comprises a plurality of horizontal and vertical reinforcing members cast into the panel following the shape of the panel.
 7. A precast reinforced concrete form for forming poured-in-situ vertical parapets of residential or commercial buildings, comprising a pair of precast reinforced concrete panels, each of the precast reinforced concrete panels having an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface, first and second vertical sides and a top end and a bottom end, wherein the form further comprises a plurality of horizontal reinforcing trusses, each of said trusses having a first longitudinal header, said header cast into one of the panels and horizontal reinforcing members extending from said header cast into the other panel and wherein each of the longitudinal headers may be further reinforced by vertical longitudinal reinforcement rods linking each of said trusses.
 8. A precast reinforced concrete form for forming poured-in-situ vertical circular columns of residential or commercial buildings, comprising a circular precast reinforced concrete panel with a hollow center, an inside surface facing the space in which the poured-in-situ concrete is to be placed, an outside surface and a top end and a bottom end wherein the form further comprises a plurality of horizontal and vertical reinforcing members cast into the panel following the shape of the panel.
 9. A method of making a form for forming poured-in-situ vertical concrete walls of residential or commercial buildings the form comprising at least one precast reinforced concrete panel, the method comprising: a. forming a mould for one of the precast panels, b. positioning a plurality of vertical reinforcing trusses off the base of the form for the first precast panel, each of said trusses having a pair of longitudinal headers, said headers to be cast into the panel, and each of said trusses having horizontal reinforcing members extending from said headers outwardly through the inside surface of said panel, c. pouring concrete into the mold with a sufficient cover to retain the pair of longitudinal headers, curing it, rotating it after reaching the required strength.
 10. A method according to claim 5 wherein after a first panel is poured and after turning it, a mould is created for a second precast panel with the ends of the horizontal reinforcing members extending from said headers in said first panel connecting to a second longitudinal header to be cast into the second panel.
 11. A system of erecting formwork for forming poured-in-situ vertical concrete walls of residential or commercial buildings comprising: a. A plurality of forms for forming poured-in-situ vertical concrete walls of residential or commercial buildings wherein the vertical walls are exterior walls below grade according to claim 2 is erected on spacers that allow for a concrete base as wide as the form. b. To ensure the loads are adequately flowing through adjacent forms, dowels can be protruding from the structure below and going in between the prefabricated panels of the forms. c. Similarly, when the forms are being erected over a concrete slab, the prefabricated panels will be placed over slab dowels that were left protruding from the slab itself. d. Also some rebar protruding from the wall below can be incorporated into the new forms being erected. e. During the erection, the forms will be lifted in place by the tower crane and then supported laterally and kept vertical by temporary props to be connected to the wall. f. Finally, when enough forms have been erected and the onsite rebar has been placed, concrete will be poured in between the precast panels until reaching the full height of the panels or could be poured in lifts, depending on the site needs and on the design.
 12. A method of constructing for forming poured-in-situ vertical concrete walls for a stairwell using form comprising at a pair of precast reinforced concrete panels said panels having an inside surface facing the space in which the poured-in-situ concrete is to be placed and an outside surface, first and second vertical sides and a top end and a bottom end, and said form further comprising a plurality of vertical reinforcing trusses, each of said trusses having a pair of longitudinal headers, said headers cast into one of said panels, and each of said trusses having horizontal reinforcing members extending from said headers outwardly through the inside surface of said panel to a second header cast into the other one of said panels, said method comprising: a. Along one end of the stairwell, a precast concrete form according to claim 2 is erected; b. After erection of the first precast concrete form, the formwork for the long wall of the stairwell is erected using the precast concrete form according to claim 2; c. The formwork for the second end of the stairwell is erected next using a precast concrete form according to claim 2; d. Lastly the formwork for the doorway side wall of the stairwell is erected using the precast concrete form according to claim
 2. 13. A method according to claim 12 further comprising once the precast concrete forms have been setup for the stairwell concrete walls, a precast landing is attached to the inside surface of the panels adjacent their top ends.
 14. A method according to claim 13 wherein a set of precast stairs can be set on the landing and floor of the stairwell. 